By Niels Jacobsen, Copenhagen, Denmark
More material gathered during recent years has shown that the hitherto held opinion of Cryptocoryne cordata Griffith, C. grabowskii Engler, C. zonata De Wit, and C. diderici De Wit as separate species is no longer tenable. They are therefore regarded as varieties of C. cordata, and deprecated from full species and placed as varieties of C. cordata. (Jacobsen 2002).
The identity and circumscription of the Cryptocoryne cordata-complex in the Malaysian region has been a matter of discussion for a number of years. With only a few collections available, it has been rather easy to distinguish between them. In recent years more material, especially from Kalimantan, has shed light on the variation and distribution, and it is my opinion that the characters used to distinguish the different entities vary to such a degree, that it is no longer reasonable to maintain the taxa at the species level.
As pointed out by Jacobsen (1985), the southern Malay peninsula, large, cordate leaved forms with a more or less yellow limb of the spathe represent what Griffith meant when establishing Cryptocoryne cordata Griffith. Specimens of C. cordata (2n=34) from Johore (the area best investigated and best represented by herbarium specimens) are not very variable in morphology, and they have brown green marmorated leaves, and long spathes with a rather smooth, yellow limb of the spathe together with a broad collar zone. C. grabowskii Engler and C. zonata De Wit from Borneo fall within C. cordata in the present circumscription. The differences being:
Var. grabowskii (2n=68) has larger, green leaves, a white appendix of the spadix, the kettle inside white, a rough to slight warty surface of the limb of the spathe, and a clearly raised, bulging collar zone.
Var. zonata (2n = 68) has purple to green, more or less bullate leaves, a purple spotted appendix of the spadix, a purple zone on the upper side of the kettle, and a more or less purple tinged limb of the spathe with the broad collar zone.
Collections from Sumatra referred to Cryptocoryne diderici De Wit have shown that it also falls within C. cordata. Var. diderici has somewhat narrow, more or less purplish leaves, a purple spotted appendix of the spadix, the kettle inside white, a limb of the spathe which has a rough surface, which is brown to brownish, and a somewhat bulging, broad yellow collar zone.
There are plants of var. zonata from Borneo, where the limb of the spathe is dark brown, and clearly demarcated from the yellow collar zone, and it is difficult to distinguish them from the Sumatra plants of var. diderici. The Sumatra plants have a bulging collar, a rougher surface of the limb of the spathe, and lack purple spots inside the kettle.
A mistake has occurred in de Wit (1990), where Abb. 50-left, labelled Cryptocoryne "cordata" has been drawn after a Korthals specimen from Borneo (L) which is actually var. grabowskii, and Abb. 551+2-right, labelled C. "grabowskii" have been drawn after Murdoch 213 (SING) (551), and Corner s.n. 15.4.1935 (SING) (552), which are specimens of var. cordata from the Malay peninsula.
The Thai material will be treated later on, when the ongoing investigations are finished.
With the overlapping and adjoining distribution and variation found, the variety level would be the most suitable for the Cryptocoryne cordata-complex, and four new combinations were proposed for the Malesian region (Jacobsen 2002):
Cryptocoryne cordata Griffith var. cordata - Aqua-Planta 27: 151 (2002).
Cryptocoryne cordata Griffith, Notulae ad Plantas Asiaticas, III (1851) 138 & Icones Plantarum Asiaticarum, III, tab. 172. - Type: Griffith 6012 (K, lecto; P), Malay Peninsula.
Cryptocoryne cordata Griffith var. diderici (De Wit) N. Jacobsen - Aqua-Planta 27: 151 (2002).
Cryptocoryne diderici De Wit, Belmontia Misc. Papers Landbouwhogeschool, Wageningen 6 (1970) 279. - Type: J. Liet (WAG, holo), misit e Malacca borealis, Octobris 1960.
Cryptocoryne cordata Griffith var. grabowskii (Engler) N. Jacobsen - Aqua-Planta 27: 151 (2002).
Cryptocoryne grabowskii Engler, Bot. Jahrb. 25 (1898) 28. - Type: Grabowski s.n. (B, lecto), Florif. m. Nov. 1881, in districtu Dussen Timor, ad flomen Siong.
Cryptocoryne cordata Griffith var. zonata (De Wit) N. Jacobsen - Aqua-Planta 27: 151 (2002).
Cryptocoryne zonata De Wit, Belmontia 13 (1970) 279. - Type: A.J. Key, s.n. (WAG, holo), 17-28.12.1961, Sg. Lumut, Brunei.